How to set common colorbar for multiplots?

Hi all,

I am using subplots to plot multiple contour plots in a single figure using for loop and using colorbar with 'Position' but it doesn't give the common values for all the plots. I have tried different solution which was given to other Matlab users but none worked.

fig=figure(1)
clf
for i=1:24
subplot(6,4,i)
contourf(x,y,z)
end
h=axes(fig,'visible','off'); 
h.Title.Visible='on';
h.XLabel.Visible='on';
h.YLabel.Visible='on';
ylabel(h,'yaxis','FontWeight','bold');
xlabel(h,'xaxis','FontWeight','bold');
title(h,'title');
colormap(jet)
c=colorbar;
c.Position = [0.93 0.168 0.022 0.7];

Can you help me with this problem?

Thanks in advance!

Answer 1

[Robert U]

Hi UTKARSH VERMA,

have a look at caxis():

[x, y] = meshgrid(0:0.1:1,0:0.1:1);
z = rand(11,11,24);

minColorLimit = min(min(min(z)));                   % determine colorbar limits from data
maxColorLimit = 24*max(max(max(z)));

fig=figure(1);
for i=1:24
    sph{i} = subplot(6,4,i,'Parent',fig);
    contourf(sph{i},x,y,i.*z(:,:,i))                % changes due to illustration purposes
    caxis(sph{i},[minColorLimit,maxColorLimit]);    % set colorbar limits
end
h = axes(fig,'visible','off'); 
h.Title.Visible = 'on';
h.XLabel.Visible = 'on';
h.YLabel.Visible = 'on';
ylabel(h,'yaxis','FontWeight','bold');
xlabel(h,'xaxis','FontWeight','bold');
title(h,'title');

c = colorbar(h,'Position',[0.93 0.168 0.022 0.7]);  % attach colorbar to h
colormap(c,'jet')
caxis(h,[minColorLimit,maxColorLimit]);             % set colorbar limits

Kind regards,

Robert

[UTKARSH VERMA]

Thanks Robert!!

It's working perfectly.

[Arnav Gupta]

Hey robert I executed this code but noticed that once a single colorbar comes for all subplots no matter how much i change its limits , there is no change in the subplots. Is it becuase the subplots limits are already specified in for loop and outer colorbar limits has no relation with these subplots??

[Robert U]

Hi Arnav Gupta,

exactly. The created colorbar is an individual object on the figure and will not change no matter what you do with you subplots. In order to change that you would have to add a listener to the colorbar that will recalculate on colormap changes within the subplots. That's far more work than recalculating the whole figure and adjust the colorbar limits.

Kind regards,

Robert

[Ashfaq Ahmed]

How can I remove the xtics and yticks? @Robert U

[Ashfaq Ahmed]

I am writing this code -

%load NBayTEMPdetmnth.mat
clf;
fig=figure(1);
t = tiledlayout(4,3); t.TileSpacing = 'compact';
for i = 1:12
nexttile
[~, hContour]=contourf(flip(NBayTEMPdetmnth(:,:,i)),25,'-','linewidth',0.5);
hold on;
end

h = axes(fig,'visible','off'); 
h.Title.Visible = 'off';
h.XLabel.Visible = 'off';
h.YLabel.Visible = 'off';
c = colorbar(h,'Position',[0.93 0.168 0.022 0.7]);  % attach colorbar to h
colormap(c,'jet')
caxis(h,[-5 20]);             % set colorbar limits

[Robert U]

Hi @Ashfaq Ahmed,

Try this:

NBayTEMPdetmnth = rand([256,256,12]);

clf;
fig=figure(1);
t = tiledlayout(4,3); t.TileSpacing = 'compact';
for i = 1:12
ah = nexttile;
[~, hContour]=contourf(ah,flip(NBayTEMPdetmnth(:,:,i)),25,'Linestyle','none','linewidth',0.5);
ah.XTick = [];
ah.YTick = [];
end
h = axes(fig,'visible','off'); 
h.Title.Visible = 'off';
h.XLabel.Visible = 'off';
h.YLabel.Visible = 'off';
c = colorbar(h,'Position',[0.93 0.168 0.022 0.7]);  % attach colorbar to h
colormap(c,'jet')
caxis(h,[-5 20]);             % set colorbar limits

Kind regards,

Robert

[Shuchi]

Thanks for the code.

Answer 2

[Adam Danz]

This is easy with tiledlayout (MATLAB R2020b or later)

tcl = tiledlayout(3,4);
for i = 1:prod(tcl.GridSize)
    nexttile()
    [X,Y,Z] = peaks(2+i);
    contourf(X,Y,Z)
    clim([-7,6])  % Important!  Set the same color limits
end
cb = colorbar(); 
cb.Layout.Tile = 'east'; % Assign colorbar location

[Diana Grisolia]

Thnks! It worked perfectly!!